1. Introduction

Photos and images constitute the largest chunk of the Web, and many include recognisable features, such as human faces, QR codes or text. Detecting these features is computationally expensive, but would lead to interesting use cases e.g. face tagging, or web URL redirection. This document deals with text detection whereas the sister document [SHAPE-DETECTION-API] specifies the Face and Barcode detection cases and APIs.

Conformance

Conformance requirements are expressed with a combination of descriptive assertions and RFC 2119 terminology.
The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL”
in the normative parts of this document
are to be interpreted as described in RFC 2119.
However, for readability,
these words do not appear in all uppercase letters in this specification.

All of the text of this specification is normative
except sections explicitly marked as non-normative, examples, and notes. [RFC2119]

Examples in this specification are introduced with the words “for example”
or are set apart from the normative text with class="example", like this:

This is an example of an informative example.

Informative notes begin with the word “Note”
and are set apart from the normative text with class="note", like this: